The Donate Now button should disappear when PayPal Donations is selected in a Two Panel or Multi Step form.

The workaround is to use a Classic Template VFB form, or use the following CSS:

section.givewp-layouts.givewp-layouts-section:has(li.givewp-fields-gateways__gateway--paypal-commerce.givewp-fields-gateways__gateway--active)~button {

display: none !important;

}